Forum for Science, Industry and Business

Sponsored by:     3M 
Search our Site:


Are bacteria making you hungry?

Over the last half decade, it has become increasingly clear that the normal gastrointestinal (GI) bacteria play a variety of very important roles in the biology of human and animals.

Now Vic Norris of the University of Rouen, France, and coauthors propose yet another role for GI bacteria: that they exert some control over their hosts' appetites. Their review was published online ahead of print in the Journal of Bacteriology.

This hypothesis is based in large part on observations of the number of roles bacteria are already known to play in host biology, as well as their relationship to the host system. "Bacteria both recognize and synthesize neuroendocrine hormones," Norris et al. write.

"This has led to the hypothesis that microbes within the gut comprise a community that forms a microbial organ interfacing with the mammalian nervous system that innervates the gastrointestinal tract." (That nervous system innervating the GI tract is called the "enteric nervous system." It contains roughly half a billion neurons, compared with 85 billion neurons in the central nervous system.)

"The gut microbiota respond both to both the nutrients consumed by their hosts and to the state of their hosts as signaled by various hormones," write Norris et al. That communication presumably goes both ways: they also generate compounds that are used for signaling within the human system, "including neurotransmitters such as GABA, amino acids such as tyrosine and tryptophan—which can be converted into the mood-determining molecules, dopamine and serotonin"—and much else, says Norris.

Furthermore, it is becoming increasingly clear that gut bacteria may play a role in diseases such as cancer, metabolic syndrome, and thyroid disease, through their influence on host signaling pathways. They may even influence mood disorders, according to recent, pioneering studies, via actions on dopamine and peptides involved in appetite. The gut bacterium, Campilobacter jejuni, has been implicated in the induction of anxiety in mice, says Norris.

But do the gut flora in fact use their abilities to influence choice of food? The investigators propose a variety of experiments that could help answer this question, including epidemiological studies, and "experiments correlating the presence of particular bacterial metabolites with images of the activity of regions of the brain associated with appetite and pleasure."

Formal publication is scheduled for the February 2013 issue of the Journal of Bacteriology.

(V. Norris, F. Molina, and A.T. Gewirtz, 2012. Hypothesis: bacteria control host appetites. J. Bacteriol. Online ahead of print 9 November 2012.)

The Journal of Bacteriology is a publication of the American Society for Microbiology (ASM). The ASM is the largest single life science society, composed of over 39,000 scientists and health professionals. Its mission is to advance the microbiological sciences as a vehicle for understanding life processes and to apply and communicate this knowledge for the improvement of health and environmental and economic well-being worldwide.

Jim Sliwa | EurekAlert!
Further information:

More articles from Life Sciences:

nachricht Novel mechanisms of action discovered for the skin cancer medication Imiquimod
21.10.2016 | Technische Universität München

nachricht Second research flight into zero gravity
21.10.2016 | Universität Zürich

All articles from Life Sciences >>>

The most recent press releases about innovation >>>

Die letzten 5 Focus-News des innovations-reports im Überblick:

Im Focus: New 3-D wiring technique brings scalable quantum computers closer to reality

Researchers from the Institute for Quantum Computing (IQC) at the University of Waterloo led the development of a new extensible wiring technique capable of controlling superconducting quantum bits, representing a significant step towards to the realization of a scalable quantum computer.

"The quantum socket is a wiring method that uses three-dimensional wires based on spring-loaded pins to address individual qubits," said Jeremy Béjanin, a PhD...

Im Focus: Scientists develop a semiconductor nanocomposite material that moves in response to light

In a paper in Scientific Reports, a research team at Worcester Polytechnic Institute describes a novel light-activated phenomenon that could become the basis for applications as diverse as microscopic robotic grippers and more efficient solar cells.

A research team at Worcester Polytechnic Institute (WPI) has developed a revolutionary, light-activated semiconductor nanocomposite material that can be used...

Im Focus: Diamonds aren't forever: Sandia, Harvard team create first quantum computer bridge

By forcefully embedding two silicon atoms in a diamond matrix, Sandia researchers have demonstrated for the first time on a single chip all the components needed to create a quantum bridge to link quantum computers together.

"People have already built small quantum computers," says Sandia researcher Ryan Camacho. "Maybe the first useful one won't be a single giant quantum computer...

Im Focus: New Products - Highlights of COMPAMED 2016

COMPAMED has become the leading international marketplace for suppliers of medical manufacturing. The trade fair, which takes place every November and is co-located to MEDICA in Dusseldorf, has been steadily growing over the past years and shows that medical technology remains a rapidly growing market.

In 2016, the joint pavilion by the IVAM Microtechnology Network, the Product Market “High-tech for Medical Devices”, will be located in Hall 8a again and will...

Im Focus: Ultra-thin ferroelectric material for next-generation electronics

'Ferroelectric' materials can switch between different states of electrical polarization in response to an external electric field. This flexibility means they show promise for many applications, for example in electronic devices and computer memory. Current ferroelectric materials are highly valued for their thermal and chemical stability and rapid electro-mechanical responses, but creating a material that is scalable down to the tiny sizes needed for technologies like silicon-based semiconductors (Si-based CMOS) has proven challenging.

Now, Hiroshi Funakubo and co-workers at the Tokyo Institute of Technology, in collaboration with researchers across Japan, have conducted experiments to...

All Focus news of the innovation-report >>>



Event News

#IC2S2: When Social Science meets Computer Science - GESIS will host the IC2S2 conference 2017

14.10.2016 | Event News

Agricultural Trade Developments and Potentials in Central Asia and the South Caucasus

14.10.2016 | Event News

World Health Summit – Day Three: A Call to Action

12.10.2016 | Event News

Latest News

Resolving the mystery of preeclampsia

21.10.2016 | Health and Medicine

Stanford researchers create new special-purpose computer that may someday save us billions

21.10.2016 | Information Technology

From ancient fossils to future cars

21.10.2016 | Materials Sciences

More VideoLinks >>>